Test for hard-to-diagnose cancers goes beyond Pap smear

Jan. 9, 2013

Written by

Liz Szabo

USA Today

WOMEN’S CANCERS

About 15,500 American women die of ovarian cancer each year, along with more than 8,000 who die of uterine cancer, according to the American Cancer Society. • Endometrial cancer is one of only a handful of cancers that are increasing in both incidence rates and deaths, according to a report released this week from the cancer society and other groups. Researchers believe rising rates of obesity, which increases the risk of endometrial cancer, are fueling the trend.

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The Pap smear, first developed in the 1940s, is often described as the world’s most successful cancer screening test.

Deaths from cervical cancer, once a major killer of American women, have fallen 75 percent since the test’s introduction.

Now, doctors are combining this grandmother of all screening tests with the latest genomic research in an effort to detect cancer of the ovaries and the endometrium, or uterine lining.

In a surprise finding, researchers discovered that cervical fluid, obtained during a Pap smear, may contain not only cells from cervical cancer, but from ovarian or endometrial cancer, as well.

Using sophisticated new methods of sequencing DNA, doctors scanned this fluid for genetic mutations found only in ovarian or endometrial cancers, according to a pilot study published online Wednesday in Science Translational Medicine.

Authors note that their study was small, with samples from just 24 endometrial cancers and 22 ovarian cancers.

Not ready for use, but positive

The research is in its earliest stages, and is nowhere close to being ready to be used, said co-author Nickolas Papadopoulos, a professor of oncology at Johns Hopkins Kimmel Cancer Center. He plans to conduct additional studies with hundreds of tumor samples.

But the test, called PapGene, appears promising, he said. It found 100 percent of the endometrial cancers and 41 percent of ovarian cancers.

Developing an early screening test for a disease as deadly as ovarian cancer is akin to finding “the Holy Grail,” said Shannon Westin, of Houston’s M.D. Anderson Cancer Center, who wrote an accompanying editorial.

That’s because ovarian cancers are typically found very late, when they are incurable, Westin said.

Early detection benefits women

Finding ovarian cancers earlier could help a lot of women, Westin said. Five-year survival rates for early ovarian cancers, which haven’t spread, are 92 percent. Overall ovarian cancer survival rates, however, are only 44 percent.

In contrast, endometrial cancers are often diagnosed early, because of symptoms such as vaginal bleeding, Westin said. Five-year survival rates for uterine cancer are 83 percent.

The study was funded by a variety of sources, including the National Institutes of Health and private charities.

Papadopoulos and several of his co-authors are co-founders of Inostics and Personal Genome Diagnostics, which has licensed some of the technical aspects involved in PapGene tests to other companies.